Transmission Component and System Description

The mechanical components of this unit are as follows:
^ A torque converter with a Torque Converter
^ Clutch (TCC)
^ A drive link assembly
^ Intermediate/4th and Lo/Reverse friction band assemblies
^ Forward, Coast, 2nd, Reverse, and Direct multiple disc clutch assemblies
^ Two planetary gear sets: Input and Reaction
^ Two roller clutches (Lo and 2nd)
^ One sprag clutch
^ One vane type oil pump
^ One control valve assembly
^ A final drive and differential assembly

The electrical components of this unit are as follows:
^ Two shift solenoid valves, 1-2 and 2-3
^ A Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid valve
^ A transmission Pressure Control (PC) solenoid valve
^ An Automatic Transmission Fluid Temperature (TFT) sensor
^ Two speed sensors: Input and Output Speed Sensor
^ An Automatic Transmission Fluid Pressure (TFP) Manual Valve Position Switch assembly
^ An Automatic Transmission Wiring Harness Assembly

Transmission Adapt Function
The 4T40-E transmission uses a line pressure control system, which has the ability to continuously adapt the system's line pressure. This compensates for normal wear of the following parts:
^ The clutch fiber plates
^ The seals
^ The springs

The PCM maintains the Upshift Adapt parameters for the transmission The PCM monitors the A/T ISS sensor and the A/T OSS during commanded shifts in order to determine if a shift is occurring too fast or too slow. The PCM adjusts the signal from the transmission pressure control solenoid in order to maintain a set shift feel. Transmission adapts must be reset whenever the transmission is overhauled or replaced. In order to reset transmission adapts, select the following:
1. Tech 2
2. Special Functions
3. Transmission Output Controls
4. Clear TAPS